Often, there is the need to obtain measurements of the proportions and levels of gases present in a periodic or time-varying gas pattern, such as the breath of a patient. Analysis of the gases present in the breath of a patient is commonly utilized as a non-invasive procedure for obtaining a representation of the proportions and levels of gases in the patient's blood. It is known that air in the deep alveolar pockets of a patient's lungs is composed of a mixture of gases which is in close equilibrium with the mixture of gases present in the patient's blood. During a patient's breath cycle, the last portion of an exhalation, i.e. the “end-tidal” portion is believed to provide the most accurate representation of the mixture of gases in the deep alveolar pockets of the lungs.
Conventional breath analyzer devices obtain a number of measurements of gas concentrations in a patient's breath over a predetermined period of time. These measurements are utilized in a mathematical curve-fitting analysis which subsequently provides an approximate measurement of the gas concentrations for discrete portions of the patients breath, including the end-tidal portion.
Accordingly, it would be advantageous to provide a system and method for analyzing the proportions and levels of one or more gases present in the breath of a patient, and which is capable of selectively analyzing only the end-tidal portion of the breath of a patient to provide an accurate direct measurement of the mixture of gases present in the patient's blood.